N-amino-2-pyridones from acetohydrazide derivatives
Abstract
The synthesis of a variety of N-amino-2-pyridones from ethoxycarbonyl acetohydrazide (1) is described. α-Benzoylcinnamonitriles (2) react with (1), in two different ways, giving rise to two kinds of N-aminopyridones (4) and (5) depending upon the cyclization taking place at the carbonyl or cyano group. Reaction of (1) with ethyl α-cyanocinnamates (10) involves cyclization at the cyano group affording the diaminopyridones (11). In contrast, ethyl malonamate (18) reacts with (10) at the ester group, leading to piperidinediones (20). Aromatic rings obtained by oxidation of some of the above compounds are also reported.